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Fungal Infections (Mycotic Disease) in Reptiles – Part 2

Green Tree PythonThe dangers posed by fungal infections are well-known to amphibian and fish keepers.  A number of fungi also attack reptiles, but many have proven difficult to detect and treat.  In Part 1 of this article I discussed how stress predisposes reptiles to attack and fungal infections in desert-adapted reptiles.

Rainforest Reptiles

Reptiles adapted to rainforests and other humid environments are not immune to fungal attack, despite the fact that fungi are common in their natural habitats.  Problems were first noted in Green Tree Pythons housed in enclosures that allowed for little air circulation.  Subsequently, we learned that these snakes must have humidity as well as air circulation if they are to remain free of respiratory infections.  I have found the same to hold true for Green Tree Boas, among others.

I advise against covering screening in order to increase humidity; the use of a humidifier or manual spraying is preferable.  The Tropicare Humidifier/Air Exchanger provides both moisture and air circulation.

Aquatic and Semi-Aquatic Snakes

Northern WatersnakeFungi thrive in damp environments, so one might expect aquatic snakes to have natural defenses against infection.  Yet many seem more prone to fungal attack than are terrestrial species. Another problematical species is the Fly River Turtle.  The skin-like coating on their shells seems especially sensitive to infection.  While at the Bronx Zoo, I experimented with salt as a cure/preventative…results were mixed.  The Diamondback Terrapin, which naturally inhabits brackish environments, is prone to shell fungus when kept in fresh water.

I well-remember my first experience with this phenomenon – a wild-caught Northern Watersnake that I kept in a largely aquatic setup developed numerous skin blisters.  Then Bronx Zoo reptile curator Wayne King answered the letter I wrote to him (imagine, the curator of a major zoo responding by mail to a 10 year old!) by suggesting I replace the water section with a bowl and provide a warmer basking site.  The blisters cleared up within 2 weeks of the change.

The aquatic Elephant Trunk and Tentacled Snakes are all-too-often plagued by stubborn fungal infections.  Treatment remains elusive, although I recall that acidifying the water proved helpful on several occasions.


Turtles seem more frequently afflicted by mycotic disease (fungal infection) than are snakes and lizards.  I’ve found shell fungus to be most common in Softshell Turtles (especially Narrow-Headed and Chinese Softshells), perhaps because their leathery shells are easily injured and open to secondary infection by fungi.

Pig-nosed TurtleHard-shelled turtles may come down with shell fungi if not provided with dry basking sites.  Species that routinely bask in the sun (Map and Painted Turtles, Cooters, Sliders etc.) should always have access to UVB light and the opportunity to thoroughly dry off.

Various topical creams and exposure to UV light have been useful in treating some types of shell fungi; work in this area is in progress now, please write in if you need information on possible treatments.

Fungal Infections of Internal Organs

Unfortunately, reptiles inflicted with internal fungal infections (i.e. liver, kidney, spleen) often exhibit few symptoms until the condition has become serious.  Weight loss is sometimes evident, so regularly weighing animals of concern is always a good idea.

Ketaconizole and other medications have proven useful for amphibians (a vet friend once cured a fungal infection in my 21 year old African Clawed Frog with Ketaconizole) and are now being tried with certain reptiles.

Further Reading

Fungal, Viral and Bacterial Infections in Snakes.


Pig-nosed Turtle image referenced from wikipedia and originally posted by Dawson


  1. avatar

    Hi Frank,
    Another question about Mata mata. Mine is eating very well, rarely waiting more than a few seconds/minutes to eat the fish I place in the tank (and immediately pressing his nose against the plastic bag as the fish are acclimating to the tank temperature).
    I wondered how often and how much I should feed him. He has about a 5-6in shell now. Ate 3 mollies today, another 4 just two days ago.
    I also noticed what appears to be sloughing of skin from his neck and legs – very fine, feathery epidermis, I think. I assume this is because he is rapidly growing, but just wanted to check with you. Good water clarity, but pH is still up above 7.

    • avatar

      Hello Bill, Frank Indiviglio here.

      Thanks for the feedback.

      It’s a tough call, and there’s lots of room for manipulation, as many reptiles are able to “adjust” their metabolisms to food availability (snakes may continue to grow despite months-long fasts!). Temperature will play a role…I don’t recall yours, sorry; please let me know; but 3-4 fish of that size every 2-3 days, with occasional longer fasts, is a good place to start.

      Matas don’t usually react so quickly, so he may be hungry, but then again some will acclimate and become bold, and may be keyed to feed by the act of presenting food. One sign of “legitimate” hunger is prowling about, seeking food – they usually do not do this unless hungry.

      Skin sloughing does occur with growth…some suggest a link to inappropriately high temperatures and over-feeding/over-growth, but I have not seen anything definitive. I do recall it seemed more common in Matas than others, and was not a problem. Check that there are no lesions, white patches, etc., but its behavior is fine so likely no problem. Please let me know your ambient temperature when you have a chance.

      Good luck and please keep me posted.

      Best regards, Frank Indiviglio.

  2. avatar

    Hi frank,

    I have a 4 inch fly river turtle and it appears that the skin is peeling off near the neck, the feet/flippers and a lil bit at the bottom plastron.. Is this normal for a turtle? It is still eating fine, still swimming and I don’t see what’s wrong with it except for the shedding skin.. Should I be worried? Or is this just a part of an aquatic turtles growth?


    • avatar

      Hi Vincent,

      Fly River Turtles are tricky; some skin and scute peeling is normal during growth; however they are also very prone to skin and shell fungal and bacterial infections, which can cause rapid peeling, and well as white spots on shell, reddened skin, etc. It can be difficult to distinguish problems from normal conditions.

      We experimented, with mixed success with a few options at the Bx Zoo. Keeping them in slightly brackish water limited fungal problems. Appx 1 tablespoon of marine aquarium salt per 5 gallons of water works well. A ph range of 7.5 – 8.3 is recommended (we used 8.0 at the zoo); water quality is critical…low nitrites/ammonia, etc.; use a good filter and do frequent partial water changes. Feeding outside of the aquarium, if turtle adjusts to that, will help keep water clean. They also favor temperature ranges of 82-86 F.

      Please keep me posted, best, Frank

  3. avatar

    Thx frank, I will assume the worst and say it’s a skin fungal infection.. Wat can I do to treat it? ( I assume the things you mentioned earlier were more prevention rather than cure )


About Frank Indiviglio

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Being born with a deep interest in animals might seem unfortunate for a native Bronxite , but my family encouraged my interest and the menagerie that sprung from it. Jobs with pet stores and importers had me caring for a fantastic assortment of reptiles and amphibians. After a detour as a lawyer, I was hired as a Bronx Zoo animal keeper and was soon caring for gharials, goliath frogs, king cobras and everything in-between. Research has taken me in pursuit of anacondas, Orinoco crocodiles and other animals in locales ranging from Venezuela’s llanos to Tortuguero’s beaches. Now, after 20+ years with the Bronx Zoo, I am a consultant for several zoos and museums. I have spent time in Japan, and often exchange ideas with zoologists there. I have written books on salamanders, geckos and other “herps”, discussed reptile-keeping on television and presented papers at conferences. A Master’s Degree in biology has led to teaching opportunities. My work puts me in contact with thousands of hobbyists keeping an array of pets. Without fail, I have learned much from them and hope, dear readers, that you will be generous in sharing your thoughts on this blog and web site. For a complete biography of my experience click here.
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